package offer;

import leetcode.common.TreeNode;

import leetcode.common.TreeUtils;

/**

* 树的子结构

*

* 输入两棵二叉树A，B，判断B是不是A的子结构。（ps：我们约定空树不是任意一个树的子结构）

*

* @author 刘壮飞

* https://github.com/zfman.

* https://blog.csdn.net/lzhuangfei.

*/

public class HasSubtreeSolution {

public boolean HasSubtree(TreeNode root1, TreeNode root2) {

if(root1==null||root2==null) return false;

return isSubtree(root1,root2)||HasSubtree(root1.left,root2)||HasSubtree(root1.right,root2);

}

public boolean isSubtree(TreeNode root1,TreeNode root2){

if(root2==null) return true;

if(root1==null) return false;

return root1.val==root2.val&&isSubtree(root1.left,root2.left)&&isSubtree(root1.right,root2.right);

}

public static void main(String[] args) {

String treeStr1 = "889##24##7##7##";

String treeStr2 = "89##2##";

TreeNode root1=TreeUtils.stringToTree(treeStr1);

TreeNode root2=TreeUtils.stringToTree(treeStr2);

boolean r=new HasSubtreeSolution().HasSubtree(root1,root2);

System.out.println(r);

}

}